Absorption refrigerating apparatus



June 4, 1935. E. GRUBER A 2,003,437

ABSORPTION REFRIGERATING APPARATUS Filed Jan. 21, 1932 ATTO PatentedJune 4, 1935 i I UNITED STATES PATENT OFFICE ABSORPTION REFRIGERATINGAPPARATUS Edward Gruber, Cleveland, Ohio, assignmto Edmund E. Allyne,Shaker Heights, Ohio Application January 21, 1932, Serial No. 588,036

7 Claims. (Cl. 62-1205) The invention disclosed in this applicationreson of the fact that less drop in P r w r lates to refrigeratingapparatus of the absorpthe still is nece ry to Dreduce appreciableretion type. turn of gas from the evaporator.

Where, in absorption refrigerating apparat s, The foregoing and otherfeatures of invention a still-absorber, condenser and evaporator arewill be apparent fromthe following description, connected in operativecycle in the order mendrawing and s. tioned, and a drain is connectedbetween the Referring to the drawing. i is a a liquor space of theevaporator and the still, there matie View Of a Ci including e v t is anundesirable tendency for, the useful reand Fig. 2 1S 8, detail view Ofthe connections bedrain back to the still rather than back through dliquid return p pe.

' the condenser, thereby shortening the refrigerat- In the drawing. irepresents a t l-absorber ing cycle by diminishing th supply of u efulrein communication witha circulatory cooling loop frigerant. ,Toovercome this defect in circuits of Comprising an p leg 2 and a w legnthis type, a by-pass is provided around the c nected to a coil shown inelevation but normaldenser, suitably loaded or trapped toward the 1y a ad horizontally This D coil may evaporator so that the returning gas mayfind an be Cooled y y Suitab e means such as the fins easier coursethrough the by-pass than through indicated at 5- During the heating p riere the drain on its way back to the still. In one ari n ir l n rou h hl p. ut it will be 2 rangement the by-passbalance leads from the set updur n vap y th r turni as evaporator to a point in the circuitsubstantially whi h n s t 6 from th as and l quid pipe 1. at or slightlybelow the normal level of the liquor This pipe extends up above thestill and to a in the still whereby, during the heating period, p int at p of a liquid s al trap 8 closed this by-pass is sealed against thepassage of gas eXeeDi fer the p p Which enter Extending 25 through it tothe evaporator and the gas must flow upward from the boiler iS the p leg9 Of a hairpin in the regular course through the condenser to entering te bottom of a header l comthe evaporator, while during the refrigeratinglnilnicating at its Other end With a down e llv cyc1e, the drain tubeconnection with the balance entering the trap a d eXtending o a po tnear tube offers the counter action for pressure on top the bOttOmnnectd to the top or gas sp of liquid in the evaporator, holding theevaporator Of this p i a rec ifier pipe I? having tW liquid inequilibrium during refrigeration, the branches entering at the p ints 3and I4 formed gas passes freely from the evaporator directly at thelewer edge M a ype rect fier and comback to the still without having topass through prising an inner tub l and outer tube l6. and overcome theresistance of the other circuit These two tubes telescope wit espect toeach frigerant to take the easier course through this tween the d a nand by-pass pipe and gas 10 through the condenser. other and are spacedvery closely to form between 35 In another form of by-pass conduit isconnected h m a v narrow n l r v y for th gas to the gasspace of theevaporator and leads back P s g throu h the rectifier. The lower and tothe connection between the rectifier and conupper edges are both sealedexcept for the pipes denser with suitable trap means in the conduitwhich enter said cavity and either both Wa ls 40 to prevent the directpassage, of gas, during the. may b p d W a multiplicity Of fi 40 heatingperiod, to the evaporator, but adapted to the outer one being as shownin the drawing. permit: the free'passage of the returning gas from. Atthe top, a rectifier condenser p p Connects the evaporator directly tothe rectifier during the th t p f th fi r w h th t p of thnrefrigerating cycle, thus lay-passing the cond denser. This of courseis much easier than a re-i The condenser is similar in structure to the45 turn through the'drain because there is no seal at rectifier andincludes an inner wall l9 and. outer the evaporator end of this by-passpipe, as is the Wall 20, very closely spaced as before, to form an casewith the drain. annular cavity between them in communication Such anarrangement is not only useful for with the pipe TheSe tWO telescoping pp overcoming one of the difllculties of a drain of'the are sealedtogether at their upper and lower 5 type mentioned, but is alsoeffective in reducing edges and the chamber within the inner wall I9 isthe time factor necessarily involved in cooling closed by suitable upperand lower caps 2| and the still at'the beginning of the refrigerating"22 pec ve y cycle. In other words, refrigeration is started catin wit tannular cavity 56 earlier in apparatus arranged in this way by reatweenthe two tubes 19 and. 20 is a suitable bottom sump 23 connected to anevaporator pipe 24 leading up to and discharging into a downwardlyinclined larger evaporator tube or pipe 25 connected to a dome 26 on thetop of the evaporator 21. The evaporator is provided with a sump 28 intowhich is run the end of a drain pipe 29. The drain pipe extends upwardlythrough the evaporator 21 and outwardly through tube 25, andcommunicates with the enlarged upper portion II of pipe 30. The lowerportion of pipe 30 is reduced in diameter as indicated by numeral 32.The reduced diameter portion 32 of the pipe 30 is joined to the gasreturn pipe 1 at a point 32' which is at approximately the normal levelor slightly below the normal level of the liquid in the still at thebeginning of the heating period.

Connected to the evaporator pipe 25 is a bypass or balancing pipe 33which communicates with the gas and liquid return pipe 1 at the pointindicated at 34, slightly below the point 32 where the drain enters thepipe I. The still ends of the .drain and by-pass pipes must be submergedat all times during the heating period, because the outgoing gas, duringthe heating period, must never pass through these pipes but must pass upthrough the trap 8, and through the rectifier into the condenser andthere be liquefied. The liquefled ammonia in the condenser, of course,is dri en up to the evaporator from time to time.

If desirable, the upper cap 2| and the lower cap 22 may be provided withwater pipes 35 and 36 respectively, which may communicate with the topand bottom of a water tank 31 for impounded or running water, to therebycool the condenser by thermosyphonic circulation.

During the heating period the ammonia gas is driven from the absorbentin the still through the loop to the bottom of trap 8 where it bubblesup through the liquor and passes out from the top thereof to therectifier and thence to the top of the condenser where it passes downand is condensed and liquefied, ultimately collected in liquefied formin the evaporator. In the meantime, however, no gas or liquor from theboiler is permitted to flow through the pipe 33 to the evaporatorbecause the point 34 is always submerged during the heating period and awater seal is formed which will prevent such passage. When the heatingperiod is over, a drop in temperature at the still lowers the pressureat this point, resulting in refrigeration at the evaporator and returnof the expanded gas through the pipe 33 directly to the gas and liquidreturn pipe, from whence it must flow to the up leg 2 and into thestill. The resistance to flow through the pipe 33 is far less than theresistance through the drain or through the condenser, rectifier, etc.,hence the gas takes this easier course through the pipe 33. In going theother way it must overcome any column of liquid in the pipe 24 and theresistance of such a column is far greater than that through the pipe33. This resistance through the by-pass is similarly less than thatcreated by the seal at the evaporator end of the drain.

The enlarged portion 3| of the drain pipe produces a very importantfunction, especially when used with smaller pipes leading to theevaporator and to the gas and liquid return pipe. The point 3|, which isthe junction of the portion 3| and the portion 32 should be high enoughto insure a complete rise in the smaller pipe 32 for the complete drainof the evaporator, and its level must be determined not only by theheight of the drain riser in and from the evaporator, but also by theheight of the column in the liquid seal trap I which of coursedetermines the resistance to the flow of gas from the still. Theenlarged central portion 3| provides for the collection of ample gaseousmedium between the upper and lower seals in the drain pipe so thatconsiderable movement of liquor in the still portion may take placewithout material compression of the gaseous medium and preventing anysiphoning of liquor'from the evaporator to the still. In this way ampledraining of the evaporator is assured.

As shown in Fig. 2, the drain pipe portion 32 is provided with anupturned end portion 32' which communicates with the pipe I at the point32". The balancing or by-pass tube 32 on the other hand has a downwardlyinclined portion 33' which enters the tube 1 at substantially the point34. In this way the entering portions of the drain and the by-pass orbalancing tube project their streams in opposite directions into thepipe 1 so that one does not influence the other.

What I claim is:

1. In absorption refrigerating apparatus, a still-absorber, condenserand evaporator connected in operative cycle in the order mentioned, apressure drain conduit having a liquid seal connection with theevaporator and communicating with the still-absorber, said drain conduitbeing enlarged intermediate its ends, and a by-pass gas returnconnection leading from the gas space of the evaporator and providedwith sealinz means effective to prevent flow toward the evaporator andarranged to permit free flow of returning gas from the evaporator towardthe still around the condenser.

2. In absorption refrigerating apparatus, a still-absorber, condenserand evaporator connected in operative cycle in the order mentioned, apressure drain conduit enlarged intermediate its ends having a liquidseal connection with the evaporator and communicating with thestillabsorber, and a by-pass gas return connection leading from the gasspace of the evaporator to the still and communicating therewith at apoint below the liquor level during the heating period.

3. In absorbtion refrigerating apparatus, a stillabsorber, condenser andevaporator connected in operative cycle in the order mentioned, apressure drain pipe having an enlarged diameter intermediate its endsleading from the bottom of the evaporator and connected in the circuittowards the still, and a by-pass gas return connection leading from thegas space of the evaporator to the still and communicating therewith ata point below the still liquor level during the heating period.

4. In absorption refrigerating apparatus, a still-absorber, condenserand evaporator connected in operative cycle in the order mentioned, aliquid seal trap connected in the circuit adjacent the still, a coolingloop for the still, a gas and liquid return conduit leading from a pointnear the top of the liquid seal trap to the loop, a drain conduitconnected to the bottom of the evaporator and communicating with the gasand liquid return conduit, and a by-pass for the gas during therefrigerating cycle, comprising a conduit connected with the gas spaceof the evaporator and communicating with the gas and liquid returnconduit.

5. In absorption refrigerating apparatus, a still-absorber, condenserand evaporator connected in operative cycle in the order mentioned, aliquid seal trap connected in the circuit adjacent the still, a coolingloop for the still, agas and liquid return conduit leading from theliquid seal trap to the loop, a drain conduit connected to the bottom ofthe evaporator and leading to the gas and liquid return conduit, and aby-pass for the gas during the refrigerating cycle, com- 5 prising aconduit connected with the gas space of the evaporator and communicatingwith the gas and liquid return pipe.

6. Absorption refrigerating apparatus as in claim 5, wherein the bypasspipe is connected in the gas and liquid return pipe below the drainconnection.

7. Absorption refrigerating apparatus as in claim 5, wherein theby-pa-ss pipe is connected in the gas and liquid return pipe below thedrain pipe, and the drain and by-pass pipes lead into the gas and liquidreturn pipe in opposite directions.

EDWARD GRUBER.

